Transnational law, since its iteration by Philip Jessup in the 1950s, has inspired a league of scholars to investigate into the scope, doctrine, sources and practice of border-crossing legal regulation. This paper reviews much of this preceding scholarly work and attempts to contextualize it in debates around global governance and global constitutionalism. These debates are no longer confined to international lawyers or political scientists. Together with anthropologists, sociologists, geographers and legal philosophers and legal theorists, these scholars have been significantly widening the scope of their investigation. The current, multi - and interdisciplinary research into the prospects of political sovereignty, democratic governance and legal regulation on a global scale suggests a further continuation of such intellectual bricolage and collaboration. The here presented paper builds on a larger research project into the methodology of transnational law and suggests that we ought to revisit legal sociological insights into the emergence of legal pluralism to make sense of today’s co-evolution of ‘formal’ and ‘informal’, ‘public’ and ‘private’ laws – and social norms.